The question mark is underused. Many times, you can make a topic sentence simpler and pithier by presenting it in the form of a question. It’s easy surgery:
of whether Munchausen syndrome was
diagnosed before the 1960s.
before the 1960s?
The exclamation point is overused. Give yourself a budget of one exclamation point for any document longer than three pages. If you must use it, use it wisely.
In traditional print shops, an exclamation point was also known as a bang. The combination of a question mark and exclamation point (?!)—seen mostly in dialogue balloons in comics—is called an interrobang. An interrobang ligature was invented in 1962 and has had an undistinguished career. It did, however, make it into Unicode. Sorry, I don’t include it in my fonts.
Never use more than one exclamation point in a row, unless you’re a teenager sending a text message. Srsly.